#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>

int main() {
    int i = 0;
    int count = 0;
    for (i = 100; i < 999; i++)
    {
        int flag = 1;
        int j = 0;
        for (j = 2; j < i / 2; j++)
        {
            if (i % j == 0)
            {
                flag = 0;
                break;
            }
        }
        if (flag == 1)
        {
            count++;
        }
    }
    printf("%d\n", count);
    return 0;
}